The field of the disclosure relates generally to aircraft engine nacelles, and, more particularly, to aircraft engine nacelles having at least one bulkhead and methods of assembling the same.
At least some known engines, such as some known jet engines and turbofan jet engines, are surrounded by a generally barrel-shaped nacelle. At least some known nacelles include a lipskin that includes a substantially airfoil-shaped exterior wall and an interior wall that at least partially defines an inlet opening of the engine. The exterior and interior walls define a cavity therebetween that generally includes a forward bulkhead that forms a first plenum defined between the forward bulkhead and the lipskin, and an aft bulkhead spaced a distance from the forward bulkhead to define a second plenum therebetween.
At least some known forward bulkheads are substantially flat in shape and are configured to provide structural support for the exterior wall of the nacelle and to provide resistance to foreign object, such as a bird, penetration through the forward bulkhead and into the second plenum. Furthermore, at least some known nacelles include insulating materials positioned proximate the forward bulkhead to reduce heat transfer of heated de-icing air from within the first plenum to the second plenum. However, such insulating materials may significantly add to the weight of the aircraft. Moreover, at least some known forward bulkheads are formed from materials that are heavy and expensive. Such materials may also be different than those of the lipskin such that the materials have different coefficients of thermal expansion. As such, the forward bulkhead and lipskin expand and contract at different rates when exposed to changing temperatures such that the aerodynamic performance of the nacelle may be reduced.
At least some known engine nacelles include aft bulkheads that are also substantially flat in shape. The aft bulkheads are generally configured to provide additional impact resistance to objects that may penetrate the lipskin and forward bulkhead. Additionally, the aft bulkhead is configured to endure a fan blade out event, that is, the aft bulkhead is configured to withstand a portion of the impact of an engine blade thrown by the engine during operation. At least some known nacelles include a crush zone component coupled radially inward of the aft bulkhead that is configured to bear the majority of the load imparted by a fan blade out event. However, these components add to the weight, cost, and complexity of the nacelle.